Shrouded elongated head multinozzle burner



Feb. 10, 1948. A. E. SHORTER ,5

SHROUDED ELONGATED HEAD MULTINOZZLE BURNER Filed Nov. 28, 1944 IN VEN TOR.

ALBERT E. SHORTER .4 TTORNE Y Patented Feb. 10, 1948 SHROUDED. ELONGATED -HEAD-1\IUL'1I-.-

NOZZLE BURNER.

Albert Edward Shorter, Sheffield, England} as-- signer to The Linde Air Products Company, New:

tion of'Ohio' Application November 28, 1944, SerialNm. 56552.7.

York, N. Y., alcorpor The application of highfltemperaturer heating flamesto asurface is usuallygattended byzthe dissipation of heat to the surrounding;atmcs:- phere. This dissipationis dueepa'rtly toadirect transmission of heat from the flames to the at"- mosphere and partlyto reflection fromathei sure face; When heating large surfacesrsuch as rolls, especially-where such surfaces: are polishemthe proportion of reflected heat may; attaina high\ value. In. surface hardening ferrous metal bodies, it is the aim to raise the-surface as rapidly as possible to the critical point and then to cool or quench the heated surface before the applied heat is dispersed.int'o the sub-surface layers. The dissipation of heat. asiafores'aidiretards the rate. at. which the surface can be raised to: the critical temperature;.and-:,as a resultzthe duration of heating must-ibeextendedwithiconsequent increase in the amount of heat dispersed into the mass of metal.

It is an object of this invention to minimise the dissipation of heat to the surrounding atmosphere when surface hardening ferrous metal bodies, to minimise loss of heat due to reflection from the heated surface and to economise in heat energy by raising the surface to the critical temperature as rapidly as possible so that the minimum amount of heat is dispersed in the mass of metal.

According to this invention, the surface hardening of a ferrous metal body comprises the steps of raising the surface to the critical point or above by directing substantially normally thereon a high temperature flame or flames, conserving the heat energy by surrounding the flame or flames with a shroud of refractory material adapted to reduce the dissipation of heat to the surrounding atmosphere and to re-direct upon the surface heat reflected therefrom and sequentially cooling the heated surface at a rate sufiicient to impart thereto the required hardened structure.

More particularly according to the invention there is provided a burner comprising an elongated head having a longitudinally extending fuel gas distribution chamber, a skirt secured to the head, refractory material housed in the skirt and providing a shrouded longitudinally extending combustion space, and a row of nozzle inserts in the head having fuel gas'orific-es for delivering gas from the fuel gas distribution chamber to the combustion space. The head also has two combustion supporting gas distribution chambers extending parallel to the fuel gas disductsleading from the tribution chamber on either side thereof, and

Great liritain December 15', 1943 1.Glaim.- (Cl. 158-214 combustion supporting gas distribution chambers to the combustionchamber, the ducts being inclined toward the center of the combustion chamber and arranged inroWs-orr either side of the fuel gasorifices.

end'of the head An'end plate isprovided at each for closing the longitudinally" extending chance"v bers and-'combustionspace; and refractoryblocks 1 line the end plates tocompletev the refractory shroud for the combustion space'.

For surface hardeningi extended surfaces, a; plurality of burnersladapted to.emit high tem perature flames. may be" arranged side by side, each burner being. provided with a. shroud in:

accordance with theainvention. For treating rolls and other large cylindricalsurfacesa, series-of: shrouded burners: be arranged to form. a compound: annular burner. adapted to surround the roll.

Apparatus constructed in accordance with the invention will now be described by way of example with reference to the accompanying drawings in which:

Fig. 1 is a part sectional view of a trating the invention; and

Fig. 2 is a section on the line 1-! of Fig. 1 to a reduced scale and extended to show the inlets for the fluids to be supplied to the burner.

For heating extended surfaces, a multi-nozzle burner may be used, the nozzles being arranged in one or more rows with orifices adapted to deliver a combustion supporting gas arranged on either side of the fuel gas nozzles. An elongated refractory shroud extending the whole length of the row of nozzles is provided in such case, the ends of the shroud being closed by refractory blocks. For treating cylindrical surfaces, the nozzle tips may be on a curve, preferably having a radius of curvature equal to that of the cylindrical surface to be treated. In view of the high temperature obtainable with multi-nozzle shrouded burners, it may be necessary to provide a cooling jacket around the burner body. A multi-nozzle burner of this type is shown in Figs. 1 and 2 to which reference will now be made.

The burner comprises an elongated head 4! having a longitudinally extending gas distribution chamber 42 connected through supply pipes 43 to a header 44. Gas supplied to chamber 42 is distributed therefrom through orifices 45 formed in a row of nozzle inserts 46 delivering the gas to a combustion chamber 41 shrouded with refractory material 48 housed in a skirt 49 secured to the head 4|. Extending through the head 4! parallel to the chamber 42 are two disburner illustribution chambers 59 adapted to be supplied through pipe 5| with a combustion supporting gas which is delivered to the combustion chamber 47 through ducts 52 leading to orifices 53 on each side of the row of burner orifices 45. The ducts are inclined toward the center of the chamber 41 and are arranged in rows on either side of the fuel gas orifices 45. The head 4! is provided with a cooling jacket 54 adapted to be supplied with cold water or other cooling fluid. The jacket 54 has a central extension 55 surrounding the gas supply pipes 43. An end plate 55 is provided at each extremity of head 4| for closing the chambers 42 and 50, the combustion space t? and cooling-jacket 54, the end plates 56 being lined with refractory blocks 51 to complete the refractory shroud for the combustion zone.

For heating extended surface zones a series of such burners may be mounted end to end across the surface. Where, as in Fig. 2, the surface S to be heated is curved, the burners are preferably correspondingly curved.

I claim:

A burner comprising an elongated head having a longitudinally extending fuel gas distribution chamber, a skirt secured to the head, refractory material housed in said skirt and providing a shrouded longitudinally extending combustion space, a row of nozzle inserts in said head having fuel gas orifices for delivering gas from said fuel gas distribution chamber to said combustion space, said head having two combustion supporting gas distribution chambers extending parallel to the fuel gas distribution chamber on either side thereof, said burner having ducts 35 leading from said combustion supporting gas distribution chambers to said combustion chamher, said ducts being inclined toward the center of said combustion chamber and arranged in rows on either side of the fuel gas orifices, an end plate provided at each end of the head for closing the longitudinally extending chambers and combustion space, and refractory blocks lining said end plates to complete the refractory shroud for the combustion space.

ALBERT EDWARD SHORTER.

REFERENCE S CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,070,889 Frickey et a1. Feb. 16, 1937 2,290,283 Jones July 21, 1942 1,298,813 Starker Apr. 1, 1919 2,365,942 Crowe Dec. 26, 1944 1,692,382 Nuss Nov. 20, 1928 1,721,484 Heyn July 16, 1929 2,143,128 Machlet Jan. 10, 1939 1,195,403 Schaap Aug. 22, 1916 1,995,122 Hess Mar. 19, 1935 5 2,005,801 Olsen June 25, 1935 2,232,809 Shorter Feb. 25, 1941 2,215,079 Hess Sept. 17, 1940 2,073,448 Fruth et a1. Mar. 9, 1937 1,890,065 Meehan Dec. 6, 1932 2,375,119 Le Tourneau May 1, 1945 1,981,850 Fisher Nov. 27, 1934 FOREIGN PATENTS Number Country Date 441,329 Great Britain Jan. 17, 1936 30,128 Austria Oct. 10, 1907 536,194 Germany Oct. 21, 1931 453,527 Great Britain Sept. 14, 1936 

